Telephone-transmitter



(N0 Modl.) H. G. ALEXANDER. TELEPHONE TRANSMITTER.

Patented Oct. 20, 1896.

ATTORNEYS UNITED STATES PATENT OFFICE.

HORACE C. ALEXANDER, OF BONHAM, TEXAS.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 569,908, dated October20, 1896.. Application filed January 6,1895. Serial No. 574,488. (Nomodel.)

To all whom, it may concern.-

Be it known that I, HORACE (J. ALEXANDER,

of Bonham, in the county of Fannin and State of Texas, have invented anew and Improved Telephone-Transmitter, of which the following is afull, clear, and exact description.

The object of my invention is to provide a simple and effectivetelephone-transmitter in which the greatest volume of sound may betransmitted without causing rattling or grating.

My invention consists in the combination, with a diaphragm and carbonbutton carried thereby, of a spring-supported flaring conicalcarbon-cell provided with a flange covered with soft material andresting on the carbon button carried by the diaphragm, the carboncellbeing filled with granulated carbon resting in contact with the carbonbutton, all as will be hereinafter fully described.

Reference is to be had to the accompanying drawings, forming a part ofthis specification, in which similar characters of reference indicatecorresponding parts in all the views.

Figure 1 is a rear elevation of my improved transmitter, and Fig. 2 is avertical transverse section. Fig. 3 is a detail view showing the springand tube for carrying the carbon-cell.

In the door A of the transmitter-box (not shown) is formed a mouthpiecea, over the aperture of which at the back of the door is placed adiaphragm B. The said diaphragm B is clamped between the metal rings CD, the ring C being provided with an internal flange or fillet b,whichreceives the diaphragm and separates it from the door, thereby formingthe resonant chamber 0. The ring B is fastened to the back of the doorA.

To the center of the diaphragm B is secured a carbon button E. To astandard d, secured to the door A, is attached a flat spring e,whichextends over the diaphragm to a point opposite the carbon button E. Inthe free end of the spring c is inserted and secured in any preferredway, as, for example, by means of soldering, a metal tube f, providedwith a flange g, having a facing h, of felt or analogous material, whichrests upon the carbon button E. In the tube f is inserted a carboncelli, which extends from a point near the carbon button E to the spring eand is open from front to rear. The forward end, or the end adjoiningthe carbon button E, is flared or made conical. The back end of the tubef is closed by a screw-cap j, and in the carboncell i and the rear endof the tube f is placed a quantity of granulated carbon Zc,which prac-Tically fills the cell and is in contact with the carbon button E. Thegranulated carbon is prevented from escaping between-the flange g andthe carbon button E by the felt I Current is taken through thediaphragm,

carbon button, through the granulated carbon and spring 6 and primarywire of an induction-coil. When sounds are uttered in the mouthpiece a,the vibration of the diaphragm causes a jarring of the granulated carbon'in the carbon-cell, thus varying the electrical conductivity of thecell and producing the variations of current necessary for thetransmission of speech.

It is obvious that the results would be the same if the flaringcarbon-cell were attached to the diaphragm and the carbon buttonattached to the spring, or if the flaring carboncell attached to thespring pressed directly upon or against the diaphragm, leaving out thecarbon button. Therefore I do not limit myself to the exact arrangementherein shown and described.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. In a telephone-transmitter, the combination of adiaphragm, a spring-supported carbon-cell furnished with a flange facedwith soft material, and a filling of granulated electrode placed in thecarbon-cell, substantially as specified.

2. In a telephone-transmitter, the combination of a diaphragm providedwith a carbon button, a spring-supported carbon-cell furnished with aflange faced with soft material, and a filling of granulated carbonplaced in the carbon-cell, substantially as specified.

3. The combination with a vibratory carbon button, of a flaringspring-supported carbon-cell having a filling of granulated carbon,substantially as specified.

HORACE C. ALEXANDER.

Witnesses:

J AS. R. MoKINNEY, A. B. SCARBOROUGH.

